fs/9p: Add fid to inode in cached mode

The fid attached to inode will be opened O_RDWR mode and is used
for dirty page writeback only.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/fs/9p/vfs_file.c b/fs/9p/vfs_file.c
index 6e1e8f43edac..e966f15f92ec 100644
--- a/fs/9p/vfs_file.c
+++ b/fs/9p/vfs_file.c
@@ -86,11 +86,30 @@ int v9fs_file_open(struct inode *inode, struct file *file)
         }
 
         file->private_data = fid;
+        if (v9ses->cache && !inode->i_private) {
+                /*
+                 * clone a fid and add it to inode->i_private
+                 * we do it during open time instead of
+                 * page dirty time via write_begin/page_mkwrite
+                 * because we want write after unlink usecase
+                 * to work.
+                 */
+                fid = v9fs_writeback_fid(file->f_path.dentry);
+                if (IS_ERR(fid)) {
+                        err = PTR_ERR(fid);
+                        goto out_error;
+                }
+                inode->i_private = (void *) fid;
+        }
 #ifdef CONFIG_9P_FSCACHE
         if (v9ses->cache)
                 v9fs_cache_inode_set_cookie(inode, file);
 #endif
         return 0;
+out_error:
+        p9_client_clunk(file->private_data);
+        file->private_data = NULL;
+        return err;
 }
 
 /**